Despite a narrow defeat, Sri Lanka will remain positive and high on confidence for Friday's second one-day international against Pakistan, vowed skipper Angelo Mathews.

Pakistan clinched a hard-fought 11-run win in the first day-night international in Sharjah on Wednesday after Sri Lankan tail-enders gave them a serious scare in chasing a daunting 323-run target.

Sri Lanka had nearly lost the match at 221-7 but Seekugge Prasanna (42) and Sachitra Senanayake (42) put on a brave 87-run stand for the eighth wicket -- a record for all Pakistan-Sri Lanka one-days -- before Pakistan averted an upset.

Mathews said his team put up a good fight.

"It is about being positive and keeping our heads high. We know we have performed well, even though we lost but the confidence is pretty high in the camp and we just want to continue with the same approach," said Mathews after the match.

Pakistan were lifted by a return-to-form 122 by Mohammad Hafeez and 73 by Sohaib Maqsood as well as debutant opener Sharjeel Khan's 61.

Sri Lanka were given a solid start by Kusal Perera (64) and Tillakaratne Dilshan (30) before the middle-order faltered.

But Mathews was happy at his team's resilience.

"I am extremely happy with the way the boys played because I think we witnessed a brilliant game. Yes, we fell short by a few runs but it was very pleasing to see the guys fighting till the end," said Mathews, who termed the Sharja wicket as difficult for bowling.

"The bowlers may retire very soon on such wickets," said Mathews of the flat Sharjah stadium pitch.

"It was very hard for the bowlers, to be honest the wicket it was really a good one for the batters. Credit should go to the Pakistanis' because with the dew they bowled pretty well."

Mathews expects a tough five-match series as well as the three Tests which follow.

"Yes we always expected a very competitive series, the one-dayers and hopefully in the Test matches as well, but we've got the skills and we have the talent in the dressing room and all we need is to get our minds right and go out there and enjoy ourselves," said Mathews.

Pakistan captain Misbah-ul Haq praised his team's batting.

"We put up a good show in batting and Hafeez led the way, but we need to improve our bowling and fielding in the next games," said Misbah.

"It was a close game in the last two, three overs. It was anybody?s game but that is the time you need to be positive and we did that."

The remaining matches will be played in Sharjah on Sunday followed by two games in Abu Dhabi next Wednesday and Friday.